Stiffness and soreness, especially in the lower back area, are common ailments of individuals who spend a great deal of time sitting down. Usually, these ailments are due to a combination of poorly designed seating and a poor posture while seated.
A correct sitting posture requires that individuals be seated with their backs straight and their weight evenly balanced on their buttocks and thighs. Unfortunately, through bad habits or a lack of muscle strength, many individuals tend to lean on an armrest or slouch down in their seats. Also the tasks people often conduct while seated require them to regularly lean forward, or to one side, to operate a keyboard, reach a telephone, or operate a vehicle.
It is desirable that a chair or portable support be provided that encourages people to adopt a correct sitting posture while allowing them the freedom to move one way or another.
Along with encouraging people to develop a correct sitting posture, the seating should support the curvature of the spine to reduce the back strain occasioned by sitting for extended periods of time. The main area where people require support is in the lower back at the lumbar region of the spine. Stiffness and soreness in the lumbar region is usually a result of the lumbar curve of the spine having to support a majority of the weight of the upper body. The larger the individual, the greater the weight the curve must support. What is required is a device that adjusts itself to support the lumbar curve of the spine according to the upper body size of the user. The support should be rigid and should not affect the ability of the device to encourage a correct seating posture.
Many forms of back support units have been developed over the years. Examples of such units may be seen in U.S. Pat. No. 2,769,485 (Shapiro) and U.S. Pat. No. 3,697,133 (Wolofski).
Typically, such units are made from a foam material that is molded to mimic the curvature of the average person's spine. Sometimes an S-shaped internal frame is also provided to mimic the spine. This frame is usually made from a plastic or fibreglass material. The curvature of the spine varies greatly with the population however and the molded or shaped units are rarely able to provide support where it is needed. The support that is provided is often not rigid enough to support the upper body weight acting upon the spine. Also, molded foam material and plastic or fibreglass frames tend to break down and lose their curvature over time to even further reduce the support provided.
The present invention overcomes these problems by providing a support unit that incorporates a frame providing lateral support to encourage a user to adopt a correct sitting posture and rigid lumbar support that automatically adjusts to a user's body size to support the lumbar region of their back.